1. Field of the Invention
The invention relates to a device for exposing photographic stripmaterial in consecutive sections of predetermined format and for separating the exposed sections, into marginless copies, for further processing the device having an exposure platform perpendicular to the axis of an optical copying device; a roller-blind shutter located immediately in front of the exposure platform, with two curtains, each adapted to be moved along a path by means of a curtain-roller, and each comprising a closing edge running at right angles to the path and adapted to move across the exposure-platform; and a feed-device for the strip-material, the feed-device containing a positioning roll operated by a drive-motor, whereby the strip-material is adapted to be fed along a track running along the path of the shutter-curtains, across the exposure-platform, to a separating device, the cutting location of which is at a fixed, predetermined distance from the optical copying axis.
2. The Prior Art
Devices of this kind are known in sundry design-variants. For the purpose of exposing the photographic material, a simple flap may be used, but normally a central or roller-blind shutter is used. Since, in projecting the picture to be copied by the copying devvice and also, in particular, in automatically positioning the photographic material for exposure, deviations from an ideal position yielding a sharply defined copy are unavoidable, the optical projection is always selected somewhat larger than the desired picture-format, and the picture is defined upon the photographic material by a mask, in order to allow for the optical and mechanical tolerances arising. The masks are either stationary mechanical restrictions, such as thin sheet-steel frames which must be changed each time the picture-format is changed, or are mobile mechanical restrictions, such as sheet-metal strips adapted to move in relation to each other which, when the picture-format is changed, maybe adjusted to the desired format manually or, more particularly, automatically by high-speed exposure devices.
In producing marginless copies from photographic strip-material, such masking is simpler per se, since masking of the longitudinal edges of the picture may be eliminated by using strip-material of a width corresponding to that of the desired picture-format, and the pictures on the strip material need be masked only at the transverse edges. However, there is also the requirement that the pictures be closely adjacent on the strip-material and that they neither overlap at the transverse edges, which would produce black transverse strips, nor are separated from each other, which would produce white strips, so that, in parting off, a single cut between two adjacent pictures will, in fact, make it possible to obtain marginless copies.
It has been found advantageous to design automatic, strip-material-processing copying devices, so-called "printers", in such a manner that it is not the finish-processed strip-material that is cut into separate copies; instead, each exposed section is immediately cut from the strip-material and is passed on for further processing into a copy. This greatly simplifies the co-ordination of copies and original and also makes it possible to interrupt the operating sequence, without delaying the finishing of copies already exposed. Sine the separating device can be arranged only in the feed-direction of the strip-material, after the shutter and the exposure-platform with the mask, the strip-material, after a section has been exposed, must first be advanced into the separating device and be correctly positioned therein, and must then, for the purpose of exposing the next section, be moved back to the exposure-platform and must be repositioned for accurate masking of the transverse edges. If the picture-format length is variable, it must also be possible to adjust the mask accurately. The accuracy of the strip-material feed, and that of the mask adjustment, must be within .+-.0.1 mm, since otherwise the aforesaid black and white transverse edges may arise. Units with constant picture-format length require precision-mechanisms and, if they are to be completely automatic, correspondingly accurate controls, and the cost of such mechanisms and controls increases considerably if the picture-format length is to be optional.
It will be understood from the foregoing that knowndevices of this kind are relatively costly and do not always ensure that no copies, or at least very few, are scrapped because of transverse edges.
It was therefore the purpose of the invention to provide a device for exposing and separating photographic strip-material, of the type mentioned at the beginning hereof, by means of which, without any external intervention in the design, and solely by programming, sections of strip-material can be exposed at separated to produce marginless, especially without unwanted black or white strips at the transverse edges, of any desired picture-format length up to the maximal dimensions of the device. The design of this device is to be relatively simple, and the mechanical design in particular is to be such that the necessary accuracy can be obtained by the use of a control consisting of micro-processors, more particularly a digital control. it is also to be possible to use photographic strip-material of different widths, so that the device may be used for any desired pictureformat, up to a maximum determined by the design itself.